Portable electronic devices, such as mobile terminals, increasingly provide a variety of communications, multimedia, and/or data processing capabilities. For example, mobile terminals, such as cellphones and personal digital assistants, may provide access to data in a wide variety of multimedia formats, including text, pictures, music, and/or video.
Text entry in mobile terminals may be difficult due to the limited input devices provided by mobile terminals. For example, while some computing devices, such as personal computers, may include a full QWERTY keyboard for alphanumeric text entry, some mobile terminals may be equipped with limited keyboards, where one key can represent more than one alphanumeric character. One such system, known as multi-tap, typically allows users to enter text using a conventional telephone key pad by pressing a key a varying number of times to cycle through several alphanumeric characters associated with the particular key.
New sensing technologies have been developed that may alter the way a user interacts with mobile terminals and/or other handheld electronic devices. For example, touch sensitive hardware, such as capacitance-sensing touch sensors, can sense the size and motion of various touch-based user inputs. Many conventional portable devices may employ such touch sensors as an overlay on top of a liquid crystal display (LCD) screen. For example, Apple's iPhone® includes a capacitance-based touch sensor that can sense single-touch and multi-touch user inputs, and as such, uses only a single physical button in its user interface, which typically functions as a “home” button to bring up the main menu.